Seismic Vulnerability Assessment of Hammer Head and Multicolumn Bridge Pier using Fragility Curve

Abstract

Beingan earthquake-prone country, Nepal has seen numerous high-magnitude earthquakes in recent years, resulting significant damage to the bridge and its components. Even after an earthquake, bridges should be able to be used for emergency and rescue operations. Fragility curves are an important technique for measuring the seismic vulnerability of bridges. Hence, this research is focused on the use of analytical method for development of fragility curve for generally used type of pier in Nepal which is hammerhead pier and multicolumn pier. Capacity of bridge is determined by non-linear static analysis and Demand parameter is estimated using non-linear time history analysis. The assumption of a log normal distribution is used to characterize fragility functions. The probability of exceedance of Slight, Moderate, Extensive and collapse damage states for hammerhead pier are 98.28%, 59.36%, 12.29%, 5.11% and 80.11%, 15.07%, 1.54%, 0.42% for MCE and DBE and those values for multicolumn pier are 97.79%, 37.91%, 5.49%, 2.01% and 72.35%, 4.22%, 0.33%, 0.08% for MCE and DBE respectively.